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DelayAtlas

Carrier route record

F9AUSORD

Frontier Airlines · Austin to Chicago

Flights
118
Period
July 2025 to June 2026
Share of route
4%
Carriers
6
C−GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier on AUS to ORD draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about 2.3 hours behind schedule. Build slack into anything you connect to. That rests on 118 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,470 at 74.9% on time.

The national on-time rate over the same period is 77.6%, so Frontier on AUS to ORD runs 13 points behind the country as a whole. Across a thousand flights that is about 125 extra late arrivals.

Key figures

On time

65.1%

Arrivals under 15 minutes late, of 109 completed flights

Avg delay

141 min

Across delayed arrivals only, not all flights

Cancelled

5.93%

National rate is 1.81%

Whole route

72.1%

Every carrier on AUS to ORD, 3,166 flights

These figures cover 118 flights between July 2025 and June 2026. Beyond the headline rate, 21.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Frontier against every carrier on AUS to ORD

Frontier flew 118 of the 3,166 flights on AUS to ORD, about 4% of it. Its 65.1% on time is 7 points worse than the route as a whole, which runs 72.1%. Ranked by on-time rate it is last of six carriers on the route, where the range runs from United at 74.9% to Frontier at 65.1%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on AUS to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,47074.9%80 min1.02%C
Envoy Airthin sample8672.6%62 min2.33%C
American Airlines1,19069.8%105 min3.11%C−
Republic Airwaysthin sample9569.7%71 min6.32%C−
Southwest Airlinesthin sample20768.8%56 min0.48%C+
Frontier Airlines (this page)thin sample11865.1%141 min5.93%C−

American Airlines cancels 3.1% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Departure window

When Frontier runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am3 flights
  • 11am–2pm49 flights78.7%
  • 2pm–5pm3 flights
  • 5pm–8pm21 flights
  • 8pm–5am42 flights55.6%

Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 55.6% on time, against 78.7% for the 11am–2pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 49 flights scheduled in it.

Across the year

Frontier on AUS to ORD through the year

  • Jul–Sep 202525 flights
  • Oct–Dec 202530 flights
  • Jan–Mar 202643 flights73.0%
  • Apr–Jun 202620 flights

Scale runs 65% to 80%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 65.1% on time across 118 flights.

Split by quarter, Frontier on AUS to ORD logged 25 flights in Jul–Sep 2025, 30 flights in Oct–Dec 2025, 43 flights in Jan–Mar 2026 and 20 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 65.1% annual figure is the one to use.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 72% of the 5,353 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Late-arriving aircraft
    72%
  • National Airspace System
    23%
  • Carrier
    3%
  • Extreme weather
    2%

72% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 5,353 reported delay minutes here, that single category outweighs weather by 31 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 5,353 reported delay minutes.

Cancellations run at 5.93%, against 1.81% nationally. That is roughly one flight in fifteen cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 21.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The 977 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg runs 66.1% on time across 118 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 118 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Frontier on AUS to ORD

Put together: the delay figures matter less here than the 5.93% cancellation rate. A late arrival costs you about 2.3 hours; a cancelled flight costs you the day. Book the 11am–2pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 109 completed flights over 12 months sit behind that.

Related

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.